Wrong
by me38242
Summary: Derek Venturi and Casey McDonald met for the first time when he was in grade 8. But teenagers change.


Derek Venturi first met his oldest step-sibling when he was in the 8th grade.

She had also been in the 8th grade.

On that day, he recalled having convinced his intellectually-challenged friend Ralph to take his place as "Derek Venturi" to show the girl around school. He, of course, loitered around as Ralph did so.

Casey had struck him as young and impressionable then. She believed Ralph's numerous poor lies, despite his many and numerous slip-ups (I mean, talking about yourself in third-person?)

However, at the end of the day, he conceded in allowing his father to marry the woman named Nora because he had had no fundamental problem with Casey.

Sure, it seemed like a nuisance to have to have her around and have a new person live in his house, but what real trouble could she possibly cause?

She had retainers, prickly spots of acne on her forehead—covered up by a mess of oily straight front bangs—wore a prep school kilt that fell below her knob-capped knees, and had an immensely irritating voice. But he could deal with her.

She wouldn't possibly bother him—not at school. They were just too different.

It was only when she actually moved in, was he proved wrong. That, perhaps, incited the epic discourse that was soon to follow.

It was not that his judgement was wrong—Derek was _never_ wrong—but that she had mislead him. Tricked him. Whatever one would like to call it.

Six months after their first meeting, the McDonalds all moved in.

In the adolescent years, people go away for summer vacation and come back to school in September completely different. For boys, their voice drops 5 octaves, height shoots up 6 inches, and suddenly become they become much better at sports. Derek relished his own growth spurt in fifth grade. He was waiting (and expecting) another.

Girls? Well, they had a more interesting repertoire of changes.

As Derek and his friends quite immensely enjoyed observing, they grew boobs, butts, make-up, hair and tighter clothing.

Oh, the wonders of adolescence and middle school. He enjoyed watching these new changes.

But Casey had never struck him as... _his_ type. That was precisely why he was phenomenally okay with her moving in with his family. Sure, she wore make-up, as all 8th grade girls did, but he couldn't actually view her as an actual girl. How could he? She was annoying, and although she wasn't a complete slob, she also wasn't particularly attractive. At least, not his _type_.

Chemistry was based 60% on appearances, and _they_ didn't have any.

He was okay with that. More than okay with that.

At the wedding, he saw Casey for the third time since the diner. (The second had been at the wedding rehearsal, but he hadn't noticed her at all then). Dressed in a sharp black tail-coat, he glanced at her from across their grandmother's lawn in Winnipeg. She was wearing a simple and airy dress in pale, pale lavender that flowed along with the breeze. Her bangs were growing out after four months, so auburn hair hit her cheekbones on either sides of her face. But she was dressed up, as all girls do on their mother's wedding.

He was tempted to walk to her and mock her for wearing make-up. Ha, as if that could help her look pretty. She would need a whole plastic surgery entourage.

The wedding had been in May.

So, when the McDonalds had into his house another 2 months later, a full six months since their first meeting at the cafe with their parents and at the dawn of the summer before 9th grade, he still remembered her as dumb, gullible Casey. Not like an actual girl.

The reason you girls become swans after summer vacations in middle school is that the changes are all sudden. You haven't seen them in a while, so you are suddenly impressed and curious about these magical and innocuously emerged breasts. In your mind, and in your memory of these girls, they didn't have any.

The thing with Casey is that it wasn't sudden. The first time Derek had met her, she was in a skirt. He _knew_ she was a girl, even if the whining didn't give it away. She just wasn't _his_ type of girl. Which was exactly why he was, theoretically, cool with her and the McDonalds moving in.

But on the first morning after they'd moved in, Derek heard footsteps walk in and move over the counter. He looked up from his bowl of cereal at the kitchen island to be faced with Casey's back; she was facing away from him, over the sink.

He frowned.

She looked different.

Now, her hair was now out of her face, her posture was straight and her body was unburdened with a gigantic backpack filled with textbooks. She wore casual clothing—not a baggy school uniform or a special occasion dress.

When he had first met her, she was in a baggy school uniform, her bangs covered half her face, and she had retainers in her mouth.

And now, he realized, she was _attractive._

And it made him angry.

The ugly duckling, Derek realized, was in actuality a swan. She had always been one, but it had just been covered up.

Why couldn't, he pondered, this realization have come to him earlier? He would've been about ten times more adamant about George not marrying Nora. He had been under the very safe and comforting assumption that his new sister would be a beastly non-girl. That was 60% the reason he had even agreed to letting her move in and George marry Nora.

He expected her to be someone who couldn't even be interested in embarrassing him or risking his popularity at school—someone who would be happy to be stuck in the library all day and hang out with science club kids in the chem lab during lunch. She had seemed like it.

His assumption, he realized with a frown as he stared at her back, was—maybe—wrong.

Derek frowned deeper, his eyebrows furrowing even more.

He frowned deeply again after that first day. Casey and Lizzie had just moved themselves into Edwin's old room. The older McDonald had just left the shower, pre-supposedly her first shower in this household. He walked in and—it smelled like vanilla and peaches. _Girl_ scents which... traditionally made his dick hard.

This didn't make him horny, though. It just got him mad. He _hated_ Casey.

His forehead creased tumultuously again when she sat down at the dinner table that first night and started speaking. Or rather, more accurately, complaining. She had the same high, tinkling, bell-sounding tones that most teenage girls have.

Derek Venturi was a fifteen year adolescent old boy.

And it was on the day after she'd first moved in that he realized that his step-sister was, in fact, a fifteen year old _girl._

* * *

Derek tried to hate her.

He tried to genuinely argue with her, to _express_ his loathing for his new step-sister.

Perhaps, if he hated her enough, he could turn off all of the irritating changes she'd made to his lifestyle.

Fruit and peaches and cream and vanilla in the bathroom shower. Bras in the laundry hamper. Color-coded _notes_ on the fridge?!

And... the existence soft skin brushing past him when he tried to reach for the butter during breakfast.

* * *

Okay, so he couldn't help it.

It _wasn't_ his fault, he stubbornly tried to convince himself.

The summer makes you more desperate, Derek reminded himself furiously and in denial, anyway. It's the heat. That had to explain it. The high temperatures.

They make you more horny.

_And_ the seclusion. It was summer break. It was just the family stuck in the house.

When the school year started, he reasoned with a relieved mental sigh, it'll all go away. All be normal again. He just needed to be around with some people—teenage _girls_—who weren't Casey.

He _couldn't_ help it, he furiously justified to himself in his head.

Yes, she was his step-sister, but they'd only been living with eachother for a two weeks now, and she'd walked out of the bathroom in a tiny towel.

She was the _only_ girl in proximity of him in his own age group. _That's_ the only reason why. No way in his right mind would he find her attractive.

He could see _everything_. Her wet hair, contributing to the drips of water slowly running down her long, freshly shaved calves.

She was a _teenage girl_.

He was a _teenage boy_. And with all due respect, she was a _stranger _to him.

He couldn't _help_ it, he thought. It's natural. He wasn't attracted to Casey—he knew that for sure. He just wasn't around any other teenage girls right now. It was summer vacation.

To add credence to that line of reasoning, he noted that her personality genuinely irritated him. She was a control-freak and honestly, kind of a priss. She was the quintessential product of rich, prissy private school breeding.

He was a played-in-the-dirt, run-of-the-mill public school guy.

They were _not_ similar. She thought the world revolved around her.

And he? Well, he kind of thought that same. The difference was that it actually _did._ Unlike her, he didn't think he was _entitled_ to things—he _knew _he _deserved_ them. A product of a superiority complex; he was the oldest after all. And he did work the hardest in the hockey rink, after all. He was _due_ the service and respect he deserved as team captain, as the eldest.

Casey on the other hand... was too self-righteous for her own good. She believed that she was always universally correct, the height of moral responsibility, and that the world revolved around her _beliefs._

So, he didn't like her. He might physically be attracted to her—she was _pretty_, even he couldn't deny that—especially when she came out of the shower—but that didn't mean he was attracted to _Casey_.

* * *

Well, you know how you do things on impulse sometimes?

Like, you don't even realize what you're doing and it just happens? It's just... not-thinking.

That's what he happened when he got into his first scramble with Casey over the remote.

Afterwards, he realized... so maybe he _was_ attracted to her. A little bit. Nothing else could explain his indiscernible and inexplicable need for close contact and physical proximity to her... which had materialized in the form of physical squabbling.

So, Derek wasn't stupid. He understood his own actions.

But it's not like he had been able to do anything about it.

* * *

"What is _wrong_ with him?" Sam asked Ralph, watching Derek walk away in his leather jacket and stereo headphones hanging around his neck.

"Huh? Well maybe his boxers have a lose stitch," he received as a response. Sam turned to Ralph, stared incredulously for a second at his friend, and then shook his head. Maybe the summer had made him stupider.

"_What? _No—I mean Derek. Yeah he's liked girls before, but he's never been _that_ callous about who he'll go out with."

"Oh," Ralph grinned widely, "Maybe he just likes boobs a lot more now!" He paused for a short moment. "I know I do!"

Sam slouched back against the locker, still staring after Derek's back and frowning.

"No. He likes making crude comments. But he definitely used to pride himself on his taste. And girl's personalities. Now, it's like he's just going after everyone and everything with breathing room between the thighs... Haphazardly."

Sure, Derek had described himself as a self-proclaimed womanizer before. But the truth was, he didn't really become a womanizer until Casey had moved in.

It had to do half with the fact that he was fifteen now, and half to do with the fact that he was getting more popular.

Casey, of course, Derek noted wryly, was oblivious to his feelings for her.

Women were weird, he realized. So oblivious. How could Casey be so oblivious to how she affected him whenever she _forgot_ to leave the bathroom door locked once every other two weeks or so? How when she forgot to wear her sleeping robe to watch late night tv in the living room one night and was sitting there with him in just a tank top, a bra, sleeping shorts and bunny slippers.

It's like he just didn't notice the changes in his face.

The truth was, Derek couldn't stand it.

He couldn't stand living with a teenage girl.

And sometimes, he was afraid she'd noticed. Noticed _him_.

How his glare would linger a moment longer during their intense fights. How he'd be staring down at the swish of her long auburn ponytail as she'd be busily (and obliviously) fixing a portrait on the wall below him.

How his mouth would drop open at breakfast whenever she'd show up wearing something particularly tight or formfitting. How he'd cover it up by stuffing cereal into his mouth.

The frustrating thing about Casey and her clothing choices, Derek decided resolutely one day, was that none of it was ever conscious. Or _revealing_. Tight, and formfitting, yes. But never revealing. If he were any normal guy, other than her step-brother, he'd think she was such a tease.

But, as her step-brother, he's seen her in different ways.

Like how when she'd walk out of the shower...

He _couldn't_ help it, he told himself.

She was basically _asking_ him to jack off to her, wasn't she!?

But he knew she wasn't. She was too oblivious.

* * *

It was somewhere around 4 months down the line, about 3 months since school had started, that he realized that she truly, really _did_ hate him.

He couldn't blame her. He really _did_ go out of his way to make her life living hell.

This was after she'd broken up with Sam and started going out with Max, that he'd realized. She actually really _did_ hate him. All that sexual tension, that chemistry—it stopped coming off from her end.

The chemistry still existed, yes. But now, he was the sole provider of it. It's like she had a mental forcefield activated. Not _actively_ choosing, but subconsciously deciding. She had no interest in him, and he could tell. He realized that soon enough.

And, for some, that made him really, really angry.

At who? He couldn't get mad at anyone. He knew he had very literally caused this to happen. Casey had had hope in him at first—at being his step-sister.

When he stole her test and wrote her own name on it, there was a shift. That was when she began truly, despicably, hating him. He had overturned any possible hope Casey had had for him to succeed. Abolished any positive expectations.

He wasn't mad at himself. He had asked for this to happen. But he was angry. And he didn't know how to deal with it. So he took it out on her—being twice as angry and cruel and standoffish as he regularly was.

At this point, he had already lost his virginity. In his head, it had been to Casey. In reality, it was in September, in the third month since she'd started living to him, to some random blonde bimbo he had been hitting on to distract himself from Casey.

It worked, obviously. For some reason, losing his virginity had changed him: it had placed him a step _above _Casey. He was above her.

He had had more sexual experience. He was older. He had sex, and it was with someone who wasn't her. He knew something more than she did. Something past all that unresolved sexual tension between them.

He felt more comfortable with sexual tension—he now knows the end result of tension.

He thought that was an accomplishment. It meant that he was over her. He was more comfortable around Casey now—less worried about her. He had a method to vent his sexual frustrations now.

She was now just a minor, irritating nuisance, a fly at the back of his head.

Except for the fact that he still liked annoying her. Still liked touching her—giving her noogies and grabbing her wrists tightly during their fights/

Once he realized that, he sat on the edge of his bed and pulled at his hair in despair. He was just about positive that his scalp was now red with irritation.

He had_ lost_ his virginity, gone out and made out with countless girls. And he was still, _still_, inexplicably in... _obsessed _with his step-sister.

* * *

_**a/n: Continue?**_


End file.
